GUNS Magazine July 2013 Digital Edition - Page 8

Light RecoiL If you need to rethInk hard-kIckIng guns. R Dave anDerson ecoil isn’t a big deal, until it is. During the 2013 Shot Show I began seeing a lot of “junk” floating in my left eye. An ophthalmologist found two horseshoeshaped tears in the retina. The little Savage 1920 in .250-3000 was a favorite of Larry Koller, author of the fine book Shots at Whitetails. It’s shortcomings are the 1:14-inch twist which won’t stabilize bullets longer than about 0.95 inch, and no provision for scope mounting. The knife was made by Rudy Ruana, bought new in about 1969. Dave bought this Ruger 77 Hawkeye .223 mainly to illustrate shooting tips in the Shooter’s Edge column. Rather to his surprise it has become one of his most-used rifles. With the outstanding Leupold 3.5-10 Mk IV scope, and bullets such as the 77-grain Sierra and 75-grain Hornady A-Max, it’ll shoot tiny groups at 100 yards, ring steel at half a mile, and do it all with negligible recoil. Emergency and follow-up laser treatment isolated the tears, greatly reducing risk of a detached retina. All the docs said I was very lucky to get treatment before the retina detached. According to the doctors a detached retina in someone with healthy eyes is most often caused a severe blow to the head, e.g. from boxing, or a vehicle accident. They didn’t seem to think recoil alone would be a cause (though I doubt they had ever fired, or seen fired, a really hard-kicking rifle). The risk factors they identified are heredity, nearsightedness, and (ahem!) age. While recoil may not be a primary cause, I’d still like to keep recoil exposure to a minimum. In this column I want to talk about getting the most performance for the least amount of recoil. The accompanying chart shows recoil velocity (RV) and recoil energy (RE) for a range of cartridges. The rifle weights and powder charges shown are typical, for comparison sake. Recoil can be reduced by lighter bullets, slower velocities, smaller powder charges, or heavier rifles. We can, of course, change combinations of all four factors. The powder charge plays a significant role in felt recoil. A larger case needs more powder than a smaller case to achieve the same velocity. Increasing velocity, assuming a constant bore size, is a game of diminishing returns. For example, a .308 Win can accelerate 180-grain bullets to 2,600 fps with 44 grains of powder. A .300 H&H with its much larger combustion chamber may take 58 grains of powder just to reach the same 2,600 fps. Assuming an 8.5-pound rifle for both, recoil velocity is 11.3 fps vs. 12.4 fps, recoil energy 17.0 ft-lbs vs. 20.5 ft-lbs. Of course the .300 H&H can shoot a 180 at 3,000 fps, which the .308 can’t. My point is, if we’re satisfied with 2,600 fps and want minimal recoil, it’s better to use a smaller case filled to capacity than to download a larger case. Rifle weight matters. Strictly speaking there aren’t any hard-kicking cartridges, only hard-kicking rifles. Extreme examples: a Savage .338 Lapua I tested was quite pleasant to shoot—hardly a surprise since all-up weight was 18.5 pounds, with 8 W W W . G U N S M A G A Z I N E . C O M • J U LY 2 0 1 3